Yarn storage and feed device utilizing correctional air jet nozzles

ABSTRACT

A yarn storage and feed device with a main body, a take-up element on which the yarn is wound, a storage surface for yarn storage, a threading device with a compressed-air feeder system and a device for activating direction-jet nozzles. At least one direction-jet nozzle is located between the point of entry of the yarn into the storage and feed device and the feed-out point from the yarn-winding element; this nozzle can be activated independently of the nozzles fitted downstream of the feed-out point so that in the event of a partial failure, where stored yarn remains on the storage surface, the yarn end can be blown below the feed-out point.

FIELD OF THE INVENTION

The present invention relates to a yarn storage and feed device providedwith directional air jet nozzles which are selectively activated tocorrect partial and total failure conditions caused by yarn breakage.

BACKGROUND OF THE INVENTION

In a yarn storage and feed device described in DE-A1-37 34 284, thethreading device comprises direction-jet nozzles and air guidancesurfaces. In case of yarn breakage, the free yarn end of the broken yarnor of a spare yarn is moved by activating all direction-jet nozzles fromthe inlet into the yarn storage and feed device through the windingelement and then along a detour path as compared with the normal yarnpath along the storage drum into the guide opening, for instance, whenthe drive is stopped in a predetermined position. In case of partialfailure with yarn breakage between the inlet and the storage drum, oneignores the fact that a regular yarn supply from which the yarn runscorrectly into the guide opening might still be present on the storagedrum. Unnecessary and time-consuming extra work is performed during thethreading operation, for continuous threading is only required in caseof total failure with yarn breakage where the yarn stored on the storagedrum has also been consumed.

In a yarn storage and feed device described in EP 0 420 176, a firstdirection-jet nozzle assembly that has simultaneously supplied theretotwo identical threads is provided in the inlet. At least one additionaldirection-jet nozzle is provided between the outlet of the windingelement and the guide opening. Irrespective as to whether after yarnbreakage there is a partial failure in which yarn is still stored on thestorage surface or whether there is total failure in the case of whichthe yarn stored on the storage surface has been consumed after yarnbreakage, both free yarn ends of the broken one yarn are eliminated incase of failure and the other yarn is newly threaded subsequently. Toeliminate yarn possibly still stored on the storage surface, the windingelement is turned back and the yarn is sucked back and discharged fromthe first direction-jet nozzle assembly.

In a yarn storage and feed device described in EP 0 269 140, partialfailure caused by yarn breakage between the reel and storage drum withat least partly correct yarn supply on the storage drum is solelyremedied in an automatic way. An auxiliary nozzle moves the yarn end ofthe broken yarn or of a spare yarn into the inlet of the yarn storageand feed device and up to the outlet of the winding element. A cuttingdevice separates an initial part of the yarn supply on the storage drumto create a free yarn end at this place. Suction air nozzles suck inboth yarn ends before a splicer connects the yarn ends. This principlepresupposes an operation control device that quickly responds to yarnbreakage. The threading device is not capable of eliminating totalfailure with an empty storage drum.

SUMMARY OF THE INVENTION

It is the object of the present invention to provide a yarn storage andfeed device of the above-mentioned kind wherein unnecessary extra workcan be avoided when the failure is eliminated and partial failure withyarn breakage can be remedied more rapidly than total failure. Underanother aspect there is to be provided a yarn storage and feed devicewhich is intelligent as to failure elimination and which is capable ofclassifying the respective type of failure and of eliminating thefailure in a specific way within as little time as possible and,optionally, in an automatic way.

The above object is attained according to a first embodiment of theinvention which utilizes a compressed-air conveying system includingdirection-jet nozzles. At least one direction-jet nozzle is arranged ina first section between a point of inlet into the device and an outlet,while at least one direction-jet nozzle is arranged in a second sectionbetween the outlet and a guide opening for the yarn. By means of anactivating device, which determines whether a total or partial failureoccurs in the system, either the direction-jet nozzles in the firstsection, or the direction-jet nozzles in the first and second sections,are activated.

If there is only a partial failure wherein the yarn is still stored onthe storage drum, the new yarn end will only be blown out from theoutlet of the winding element to some extent so that it can be knottedwith the free end remaining on the storage drum, optionally by anautomatic knotting device. The other available direction-jet nozzles arenot activated, so that the yarn stored on the storage drum will not bedestroyed, entangled or eliminated and there will also not be animpairment of the yarn along the further yarn path downstream of thestorage drum. Partial failure can be remedied within a short period oftime without any time being wasted on the elimination of the existingyarn supply. By contrast, in case of total failure in which the yarnsupply on the storage drum has been consumed, the new yarn end is movedfrom the inlet of the yarn storage and feed device up to the guideopening. In case of partial failure any troublesome elimination of theyarn material still stored does not take place.

In a second alternative embodiment, the activating device consists oftwo activating-device parts can be gathered from claim 3. To eliminatetotal failure both parts of the activating device are used. By contrast,only one activating-device part is used for eliminating partial failurewhere the yarn is still correctly stored on the storage drum.

According to a further feature of the invention, in case of partialfailure, e.g. yarn breakage in the hollow shaft of the winding elementor in the transition region from the winding element to the drum surfaceor upstream of the yarn storage and feed device, there is a yarn supplyon the storage surface. The yarn leading to the consumer still assumes astable position. The condition that the activating-device part foreliminating partial failure should only be activated in such rotarypositions of the winding element in which the threading position isabsent ensures that the still intact yarn supply is not noticeablyaffected by the follow-up yarn and the air flow, but can still be usedafter knotting of the two free ends. Improved access to the blown-inyarn end might then be possible as well. It may be important that incase of partial failure the winding element is stopped in a rotaryposition in which the blown-in yarn end is positioned at or after aknotting or splicing device and that it is connected to the yarn on thestorage drum rapidly and in an unobstructed way. This saves idle timesfor the consumer.

According to a still further feature, in a constructionally simpleembodiment, in case of failure where the operation of the yarn storageand feed device is stopped an operator decides whether there is totalfailure or partial failure. The operator moves the change-over switchinto the respective position for activating the threading device and foreliminating the failure.

According to still a further feature, the operation control devicedecides either on the basis of signals available to said device or,e.g., through remote control or through an operator's manipulation,which direction-jet nozzles are activated to eliminate partial failureor total failure.

According to another feature, in an embodiment of an automatic type, thedesire for substantial automation of the operation of yarn storage andfeed devices is taken into account. During operation of the device andeven after stoppage thereof, the classifying device exploits stillexisting signals for classifying the failure and for discriminatingwhether the yarn end must be moved only up to the storage drum or rightaway to the guide opening. The failure is eliminated in response to thespecific type of failure with a minimum of time and in an automatic way.

Another feature is of special advantage because the failure classifyingdevice uses signals which exist at any rate or are produced specificallyduring failure and which indicate, for instance, whether the storagedrum is empty or still filled.

This applies also to the alternative feature where the winding elementneed only be moved into the total-failure threading position in case oftotal failure. In case of partial failure the winding element remains ina different position which is of advantage to this type of failure. Anintelligent system which is capable of making a distinction between thedifferent types of failure and eliminates every failure in a time-savingand very simple manner is thereby created to copy with both cases.

Finally, the invention is simple from a constructional point of view,the capacity of the microprocessor of the operation control device or ofthe operation control device itself is used for this additional purpose.The elimination of a failure irrespective of whether this is a partialfailure or a total failure only requires a short down-time of the yarnstorage and feed device and the downstream consumer. In case of partialfailure the yarn material need not be disposed of on the storage drum.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the subject matter of the invention shall now beexplained with reference to the drawing, in which:

FIG. 1 is a longitudinal section through a first embodiment of a yarnstorage and feed device;

FIG. 2 is a longitudinal section through a modified embodiment; and

FIG. 3 is a longitudinal section through a modified embodiment.

DETAILED DESCRIPTION

A yarn storage and feed device 1 as shown in FIG. 1, which serves, e.g.,to supply a weft yarn to a gripper or projectile weaving machine (notshown), and includes a main body 4 which supports a drive motor for ahollow shaft 6. A cover 7 is fixed at the feed end (feed-in point orinlet Z) of the main body 4. A concentric ring 10 is arranged on thehollow shaft 6. A channel-shaped take-up element or winding element 9leads from the interior of the hollow shaft 6 to a feed-out point oroutlet 11. Permanent magnets 13 are aligned in the main body withpermanent magnets 15 which are provided in a storage drum 14 that iscoaxial with hollow shaft 6. Storage drum 14 is rotatably supported onthe hollow shaft 6 (bearings 46) and is blocked against co-rotation bypermanent magnets 13, 15. The storage drum 14 defines a storage surface17 for yarn storage V which consists of adjacent, possibly separatedwindings of a yarn Y, the windings being applied by the winding element9. An arm 20 of the main body 4 extends alongside and in spacedrelationship with storage drum 14. It holds a centric guide opening 22and serves to accommodate yarn sensors (not shown) which serve tomonitor and control the operation and to produce signals for a controldevice (not shown). Guide opening 22 may be a closed or slotted yarneyelet or also the inlet of a main nozzle (not shown) of the weavingmachine. The guide opening 22 may also be arranged on a holding deviceseparated from the main body 4.

A compressed-air feeder system serves as a threading device E. Apressure source 25, e.g. a fan or a compressed-air storage means isprovided for supplying compressed air. Pressure source 25 is connectableto a plurality of stationary direction-jet nozzles 32, 33, 37, 73 alongthe yarn path via an activating device A and supply lines 26, 27, 28 andoptionally 76, in which volume or pressure control valves 30 are, forinstance, arranged. The first direction-jet nozzle 32 that aims athollow shaft 6 to move yarn Y through hollow shaft 6 and winding element9 beyond outlet 11 is arranged in inlet Z. The next direction-jet nozzle33 is arranged in the area of the circular path of outlet 11 andoriented approximately axially relative to a tube 52 which isstationarily arranged on arm 20 and slotted on the inside longitudinallyor obliquely. A yarn brake F which is arranged on arm 20 and rests withbrake elements 48 on the storage drum 14 extends through tube 52.Another direction-jet nozzle 37 which is oriented approximately radiallyto the inside can be arranged at the outlet of tube 52. Finally, anotherdirection-jet nozzle 73 which is oriented in FIG. 1 to the right may bearranged in guide opening 22. At least nozzle 73 can be dispensed within many cases.

On main body 4, a locking pin 61 can be slid into a recess 62 of ring10, e.g. by means of a magnet, to position the outlet 11 in the area ofdirection-jet nozzle 37 when yarn Y has to be transported up to guideopening 22 (total-failure threading position). To this end, the drivemotor (not shown) is rotated forwards or backwards by the operationcontrol device at creep rate until the extended locking pin 61 locks.There may be a plurality of recesses 62 disposed in ring 10 to keepoutlet 11 in at least one predetermined position in case of both totalfailure and partial failure. It is also possible to control thesepositionings electronically by means of the control device in the drivemotor.

In the illustrated embodiment, the activating device A comprises a valve8 which can be switched by means of a solenoid 19 against resilientforce between a blocked position and a passage position, as well as aswitching device 18 which is switchable from a zero position N (shut-offposition of valve 8) into a total-failure position I and into apartial-failure position II. Furthermore, the activating device Aincludes inhibiting valves 16, 21 in supply lines 27, 28. In position Ivalves 8, 16, 21 are switched to passage. In position II, only valve 8is switched to passage whereas valves 16, 21 are blocked. The activatingdevice A is manually operable in FIG. 1. It is possible to operate theactivating device A in a remote-controlled way. Furthermore, it couldalso be operated by the operation control device (not shown).

During normal operation, yarn Y passes from inlet Z through the windingelement 9 into supply V and from said supply through yarn brake F andguide opening 22 to the consumer. The above-mentioned yarn sensorsmonitor, for instance, the size of supply V and transmit signals to theoperation control device for activating or deactivating the drive inresponse to yarn consumption and the resultant change in the size of thesupply or for controlling the speed of said drive.

In case of yarn breakage which is indicated by yarn sensors (not shown),the yarn storage and feed device 1 as well as the downstream consumerare deactivated and the failure is reported. An operator checks whetheror not yarn supply V still exists on the storage surface 17. If supply Vis still present, this is a case of partial failure. The activatingdevice A is by the operator into position I for the elimination thereof.The yarn end of the broken yarn or a spare yarn is blown by means of thedirection-jet nozzle 32 beyond outlet 11 and then linked with the yarnend of supply V, for which purpose an automatic splicer may optionallybe provided. The activating device A is then switched into the neutralposition N again and operation is resumed. Partial failure can beremedied in any rotary position of the winding element 9. However, thewinding element 9 is expediently positioned, e.g., by the locking pin61, in a predetermined partial-failure threading position.

If there is total failure with an empty storage surface 17, the operatorwill decide whether to switch the activating device A into position II,so that all intended direction-jet nozzles are activated in thetotal-failure threading position of the winding element 9 and the yarnend is blown from inlet Z into guide opening 22, i.e. with the help oftube 52 to bypass the obstacle presented by yarn brake F. The lockingpin 61 is locked in this case. Upon elimination of the total failure thelocking pin 61 is unlocked and operation is resumed.

In the embodiment of the yarn storage and feed device 1' according toFIG. 2, the threading device E operates automatically. Theconstructional configuration of device 1' largely corresponds to that ofFIG. 1 so that corresponding parts have been designated by the samereference numbers.

Downstream of the solenoid valve 8, the activating device A comprises anon-off valve 56 which is switchable by means of a magnet and connectsonly the supply line 26 to the pressure source 25 in the one positionwhereas it connects the supply line 26 and the supply lines 27, 28 tothe pressure source 25 in the other switching position. Two yarn sensors50, 51 of any desired construction are arranged in arm 20 (only one yarnsensor could also be used for this purpose). The sensors sense the sizeof supply V on the storage surface 17 and send signals to the operationcontrol device designated by 52, which is thermally insulated withrespect to the drive motor, so as to indicate whether the supply has aspecific maximum or minimum size. The operation control device 52controls the drive motor (not shown) by means of these signals duringnormal operation. The operation control device 52 contains amicroprocessor 53 which processes operation-specific parameters and yarnsensor signals. Moreover, a failure classifying device 54 is integratedinto the operation control device 52, or the microprocessor 53, whichincludes a circuit 55 for activating the actuating magnet of the on-offvalve 56.

In case of failure caused by yarn breakage the classifying device 54determines whether this is a partial failure or a total failure, forinstance on the basis of signals from the yarn sensors 50 and/or 51.This can, e.g., be accomplished in such a way that the signals from theyarn sensors 50, 51 which represent the presence of supply V are usedfor determining a partial failure whereas missing signals from the yarnsensors 50, 51 or signals from a separate yarn sensor used duringoperation or only in case of failure are used for determining totalfailure with an empty storage surface 17. The on-off valve 56 isoperated or not in response to the failure sensed, so that all supplylines 26, 27, 28 are connected to the pressure source 25 for activatingall direction-jet nozzles in case of total failure as soon as valve 8 isoperated, whereas the on-off valve 56 is not operated and only supplyline 26 is connected in case of partial failure. At least in case oftotal failure, the drive motor is still moved at creep speed to such anextent that locking pin 61 locks. As soon as the yarn end has passedfrom inlet Z to guide opening 22, operation is started again and lockingpin 61 is retracted before. At the same time, the activating device A isdeactivated by switching valve 8.

Alternatively, the respective threading position of the winding element9 could also be used by the classifying device 54 as a criterion ofdecision because the total threading position is only employed in caseof total failure whereas in case of partial failure the yarn end isblown in in every rotary position or in the partial-failure threadingposition of the winding element. To make the decision easier, anotheryarn sensor which is used during operation or an independent failurealarm could be used as well.

The yarn storage and feed device 1" according to FIG. 3 differs from thetwo preceding embodiments by a measuring device M for determining thelength of the yarn removed, e.g., for the weft yarn supply to ajet-weaving machine (not shown). Instead of the direction-jet nozzles,stationary ring nozzles 33', 35 and 37' are provided for making the yarnend, which exits from outlet 11, independent of the rotary position inwhich the winding element 9 has been stopped, namely by means of aircurtains 39, 40, 38 relative to guide opening 22. The measuring device Mis ring-shaped and supported in arm 20. The guide opening 22 is arrangedon a separate holding device 75. Stop elements 24 are circumferentiallydistributed and movably supported in the measuring device M. Each ofstop elements 24 is movable by an actuating magnet (not shown) from aretracted position leaving a passage gap L radially through the passagegap L up to storage body 14 to block the withdrawal of the yarn in theknown manner as soon as the desired withdrawal length has been reached.The detailed construction of the measuring device M and its function aredisclosed in EP-A 2-101 110, which is herewith referred to. Afunnel-shaped guide surface 42 arranged upstream of the ring nozzle 35serves to guide air curtain 39.

The activating device A for the threading device E comprises a rotaryslide valve 16' which can be operated manually by means of a lever 18'and which has three switching positions. In the first switching positionthe pressure source 25 is separated from all supply lines 26, 27, 28 andthe additional supply line 29 to ring nozzle 35. In the second switchingposition, only supply line 26 is connected to pressure source 25. In thethird switching position, all supply lines are connected to pressuresource 25.

In case of failure the rotary slide valve 16' is adjusted by an operatorin response to the presence of total failure or partial failure foreliminating said failure. Instead of the manually operable activatingdevice, the activating devices according to FIGS. 1 and 2 could beprovided for permitting semi-automatic or fully automatic operation.

Although a particular preferred embodiment of the invention has beendisclosed in detail for illustrative purposes, it will be recognizedthat variations or modifications of the disclosed apparatus, includingthe rearrangement of parts, lie within the scope of the presentinvention.

We claim:
 1. A yarn storage and feed device for a textile machine,comprising:(a) a main body; (b) a yarn winding element supported on saidmain body and drivingly supported for rotation; (c) a storage drumprovided with a storage surface thereon for a yarn supply consisting oftangential windings of yarn wound upon said storage surface, the yarnbeing withdrawn endwise of said storage drum and through a guideopening; (d) a threading device which comprises a compressed-airconveying system that includes direction-jet nozzles provided between apoint of inlet into said yarn storage and feed device and said guideopening, at least one first said direction-jet nozzle being arrangedbetween said point of inlet and an outlet of said winding element, andat least a second said direction-jet nozzle being arranged downstream ofsaid outlet; and (e) an activating device for activating saiddirection-jet nozzles, said activating device including means fordefining two operating modes including (1) a partial-failure mode whichrepresents a condition wherein yarn is still stored on said storage drumafter a yarn breakage has occurred between said inlet and said storagedrum and (2) a total-failure mode which represents a condition wherein ayarn breakage has occurred and said yarn supply has been totallyconsumed from said storage surface, said activating device having meansfor activating only said first direction-jet nozzle when said activatingdevice is in said partial-failure mode, said activating device havingmeans for activating said first and second direction-jet nozzles whensaid activating device is in said total-failure mode, whereby in theevent of a partial failure the yarn is blown downstream of said outletand in the event of a total failure the yarn is blown from the point ofinlet to the guide opening.
 2. A yarn storage and feed device accordingto claim 1, wherein said activating device includes first and secondactivating parts, said first activating part being connected to saidfirst direction-jet nozzle and said second activating part beingconnected to all of said direction-jet nozzles between said outlet andsaid guide opening, wherein said first and second activating partsactivate, respectively, the direction-jet nozzles to which they areconnected.
 3. A yarn storage and feed device according to claim 2,wherein said means for defining the operating modes of said first andsecond activating parts of said activating device is dependent upon arotary position of said winding element.
 4. A yarn storage and feeddevice according to claim 3, wherein said activating device includesmeans for operating said first and second activating parts in saidtotal-failure mode when said rotary position of said winding elementcorresponds to a predetermined threading position, and said activatingdevice includes means for operating said first and second activatingparts in said partial-failure mode when said rotary position of saidwinding element corresponds to a non-threading position.
 5. A yarnstorage and feed device according to claim 2, wherein a manuallyoperable change-over switch is provided for said first and secondactivating parts.
 6. A yarn storage and feed device according to claim2, further including an operation control device that controls saidfirst and second activating parts.
 7. A yarn storage and feed deviceaccording to claim 9, wherein said activating device includes means foroperating said activating device in said total-failure mode when saidrotary position of said winding element corresponds to a predeterminedthreading position, and said activating device includes means foroperating said activating device in said partial-failure mode when saidrotary position of said winding element corresponds to a non-threadingposition.
 8. A yarn storage and feed device according to claim 2,wherein said second directional-jet nozzle includes a saiddirectional-jet nozzle disposed adjacent the outlet and a further saiddirectional-jet nozzle disposed downstream thereof for directing theyarn toward the guide opening.
 9. A yarn storage and feed deviceaccording to claim 1, wherein said means for defining the operatingmodes of said activating device is dependent upon a rotary position ofsaid winding element.
 10. A yarn storage and feed device according toclaim 1, wherein a manually operable change-over switch is provided forswitching said activating device between said modes.
 11. A yarn storageand feed device according to claim 1, further including an operationcontrol device that controls said activating device.
 12. A yarn storageand feed device according to claim 11, further including at least oneyarn sensor and a failure classifying device which is in communicationwith said activation device, wherein said failure classifying deviceprocesses signals from said at least one yarn sensor, said signals beingindicative of a partial failure or total failure condition in said yarnstorage and feed device, whereby said activating device includes meansfor automatically placing said activating device into one of saidpartial-failure and said total-failure modes.
 13. A yarn storage andfeed device according to claim 12, wherein said at least one yarn sensoris a yarn supply size sensor, and said signals processed by said failureclassifying device represent either a partial failure condition wherestored yarn (V) remains on said storage surface or a total failurecondition where no yarn remains on said storage surface.
 14. A yarnstorage and feed device according to claim 12, wherein said windingelement possesses a predetermined threading position, and said failureclassifying device includes means for determining said partial-failurecondition and total-failure condition of said yarn storage and feeddevice by the displacement of said winding element into one of atotal-failure threading position and a partial-failure threadingposition.
 15. The yarn storage and feed device according to claim 12,wherein said failure classifying device is incorporated into saidoperation control device.
 16. A yarn storage and feed device accordingto claim 1, wherein said second directional-jet nozzle includes a saiddirectional-jet nozzle disposed downstream of the outlet and at theguide opening.
 17. A yarn storage and feed device according to claim 1,wherein the activating device includes a flow control valve shiftablebetween first and second flow-controlling positions which respectivelycorrespond to said partial-failure and total-failure modes, said flowcontrol valve including means for supplying air solely to said firstdirectional-jet nozzle when said flow control valve is in said firstposition, said flow control valve including means for supplying air toboth said first and second directional-jet nozzles when said flowcontrol valve is in said second position, said flow control valve beingmovable into a third position and including means for isolating all ofsaid directional-jet nozzles from the supply of air when said flowcontrol valve is in said third position.
 18. A yarn storage and feeddevice according to claim 17, wherein an operating device is coupled toand effects switching of said flow control valve between said positions.